A cholesteryl thiazolothiazole derivative for colorimetric sensing of Cu2+ and its sol–gel transition

• A new thiazolothiazole derivative 1 bearing aryl amine groups linked with four cholesteryl units was synthesized.
• Chol-TZTZ (1) was studied as a selective chemosensor system for Cu2+ and as a new supramolecular gel system.
• Chol-TZTZ showed a selective colorimetric change from green to blue upon the addition of Cu2+.
• The unique color change in gel state via the radical formation could be induced by electrolysis.

In the current work, a new thiazolothiazole derivative Chol-TZTZ (1) was synthesized, in which a thiazolothiazole bearing aryl amine groups was linked with four cholesteryl units. Thiazolothiazole derivative 1 displayed a unique colorimetric change from green to blue upon the addition of Cu2+via the formation of organic radicals. UV absorption maximum was changed from 395 nm to 700 nm when Cu2+ was added. Among the various solvents, cyclohexanone could induce gelation of compound 1. π–π interaction between the thiazolothiazole core and van der Waals forces between the cholesteryl group should be involved in the molecules self-assembly of the gelator chol-TZTZ into fibrous superstructures.

The organo radical formations of thiazolothiazole derivative Chol-TZTZ (1) in sol as well as gel state were achieved by the addition of Cu2+ and electrolysis.Figure optionsDownload as PowerPoint slide